Smores Pop Tart Slab Pie
For the Crust (chilled for at least 3 hours) or 2 sheets of puff pastry, thawed to room temperature:
- 3 3/4 cups all-purpose flour
- 3 Tablespoons granulated sugar
- 1/2 teaspoon kosher salt
- 1 1/3 cup unsalted butter, COLD (NOT room temperature), cut into pieces
- ¾ cup + ½ Tablespoon ice water
For the Marshmallow OR 3 cups Marshmallow fluff
- ¾ cup granulated sugar
- ½ cup light corn syrup
- ¼ cup water
- ⅛ teaspoon kosher salt
- 2 large egg whites, at room temperature
- ¼ teaspoon cream of tartar
- 1½ teaspoons vanilla extract
For the Chocolate Filling:
- ¼ cup unsweetened cocoa powder
- ⅓ cup heavy cream
- ⅔ cup dark chocolate, chopped (or dark chocolate chips)
- 2 tablespoons granulated sugar
- 1 tablespoon butter, cubed
- pinch kosher salt
- Pie Crust
- Marshmallow Fluff
- Chocolate Filling
- ¼ cup graham cracker crumbs
- 1 egg, lightly beaten + 1 teaspoon water
To make the pie crust (if not using puff pastry):
1. In a food processor, add the flour, sugar, and salt and mix together. Add in the chopped pieces of cold butter. Pulse with your processor until you have coarse crumbs. Slowly drizzle the ice water over the dough, a tablespoon or so at a time, pulsing with your processor, until dough sticks together when pinched (you may not use all of the water).
2. Form the dough gently into 2 loose balls, wrap tightly in plastic wrap, and chill in the fridge for a minimum of 3 hours or as long as overnight. Make your filling when you are almost ready to use your dough.
4. For the Marshmallow (if not using premade fluff): Stir together the sugar, corn syrup, water, and salt in a small saucepan over high heat. Bring the mixture to a boil, stirring often, until it reaches 240 degrees F on a candy thermometer. Be careful not to let the mixture bubble overturn the heat down if you need and keep a watchful eye over it. This should take around 10 minutes.
5. Place the egg whites and cream of tartar in the bowl of a stand mixer fitted with a whisk attachment. Start whipping the egg whites to soft peaks on medium speed. You want to have the egg whites whipped and ready to go, waiting for your syrup to be drizzled in. If they’re whipping faster than your syrup is coming to temperature, just stop the mixer until the syrup is ready.
6. When the syrup reaches 240 degrees F, reduce the mixer speed to low and slowly drizzle about 2 tablespoons of syrup into the egg whites to warm them. If you add too much syrup at once, the whites will scramble. Slowly drizzle in the rest of the syrup, a bit at a time.
7. Increase the speed to medium-high and whip until the marshmallow fluff is stiff and glossy, about 7 solid minutes. Don’t try to speed this process up! Add in the vanilla and whip 2 minutes more. Use the fluff immediately or refrigerate stored in an airtight container for up to 2 weeks
8. For the Chocolate: In a double boiler, combine your cocoa powder, heavy cream, chocolate, sugar, butter, and salt. Stir over medium-low heat constantly until everything is melted and smooth. Remove from the heat and set aside. The mixture will thicken up as it cools down, making it easy to spread over your pie crust later.
9. For Assembly: Remove your crust from the refrigerator to allow for easier rolling. Preheat your oven to 400 degrees F. Grease a 9 1/2 x 6 1/2-inch baking sheet or jelly roll pan.
10. Roll out your first ball of dough into a rectangle bigger than your pan. Transfer it to your baking pan. If using puff pastry, transfer it, once thawed, to your jelly roll pan.
11. Spread your chocolate mixture over the dough. Sprinkle ¼ cup crushed graham cracker crumbs over the top of the chocolate. Roll out your second pie crust and gently place it over the top. Crimp the edges together, discarding any scraps. Use a fork to make a pattern in the top of the pie (see photos), like a traditional s’mores Pop-Tart.
12. Beat together your egg and water and brush the top of the pie with it. Place the pie in the oven, then reduce the heat to 375 degrees F. Bake for 30 minutes, until golden brown and shiny on top. Remove from the oven and allow to cool completely.
13. Spread the marshmallow fluff on top of the pie, once cool. Using a blow torch, torch the top of the marshmallow. Top with more graham cracker crumbs, if desired.